Catheter device with detachable distal end

ABSTRACT

An atherectomy catheter includes an elongate catheter body, a cutter at a distal end of the catheter body, and a nosecone attached to a distal end of the catheter body. The cutter is configured to excise tissue from the body. The nosecone is configured to hold tissue excised from the cutter. The nosecone includes a distal section, a proximal section, and a connection mechanism that is configured to allow the distal section to attach and detach from the proximal section during use. The distal section includes a plug configured to sit within an inner diameter of the proximal section when the proximal section is connected to the distal section.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application No. 62/345,483, filed Jun. 3, 2016, and titled “DETACHING NOSECONE FOR CATHETER DEVICE,” the entirety of which is incorporated by reference herein.

This application may be related to PCT Application WO 2014/142954 entitled, “TISSUE COLLECTION DEVICE FOR CATHETER” filed on Mar. 15, 2013, which is herein incorporated by reference in its entirety. This application may also be related to U.S. patent application Ser. No. 13/175,232, filed Jul. 1, 2011, titled “ATHERECTOMY CATHETERS WITH LONGITUDINALLY DISPLACEABLE DRIVE SHAFTS,” now U.S. Pat. No. 9,345,510, which is herein incorporated by reference in its entirety.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

FIELD

This application is related to tissue collection devices that can be used with occlusion-crossing devices or systems such as atherectomy catheters. In particular, described herein are nosecones that can be used with catheter devices where the connection does not interfere with the catheter device cutter and its function of cutting and clearing out debulked tissue.

BACKGROUND

Peripheral artery disease (PAD) affects millions of people in the United States alone. PAD is a silent, dangerous disease that can have catastrophic consequences when left untreated. PAD is the leading cause of amputation in patients over 50 and is responsible for approximately 160,000 amputations in the United States each year.

Peripheral artery disease (PAD) is a progressive narrowing of the blood vessels most often caused by atherosclerosis, the collection of plaque or a fatty substance along the inner lining of the artery wall. Over time, this substance hardens and thickens, which may interfere with blood circulation to the arms, legs, stomach and kidneys. This narrowing forms an occlusion, completely or partially restricting flow through the artery. Blood circulation to the brain and heart may be reduced, increasing the risk for stroke and heart disease.

Interventional treatments for PAD may include endarterectomy and/or atherectomy. Atherectomy offers a simple mechanical advantage over alternative therapies. Removing the majority of plaque mass (e.g., debulking) may create a larger initial lumen and dramatically increases the compliance of the arterial wall. As a result, stent deployment is greatly enhanced.

While atherectomy may provide a minimally invasive solution to clearing the way for placement of stents within initially blocked arteries, there remains a need to improve certain aspects of atherectomy catheters presently available. For example, tissue collection and/or tissue removal from the arteries is a common challenge during atherectomy procedures. One mechanism for handling debulked tissue is to collect the tissue in a distal nosecone or collection chamber of the device. However, removing the tissue from the collection chamber or cleaning the chamber remains difficult. Accordingly, an atherectomy catheter that addresses some of these problems is desired.

SUMMARY OF THE DISCLOSURE

In general, in one embodiment, an atherectomy catheter includes an elongate catheter body, a cutter at a distal end of the catheter body, and a nosecone attached to a distal end of the catheter body. The cutter is configured to excise tissue from the body. The nosecone is configured to hold tissue excised from the cutter. The nosecone includes a distal section, a proximal section, and a connection mechanism that is configured to allow the distal section to attach and detach from the proximal section during use. The distal section includes a plug configured to sit within an inner diameter of the proximal section when the proximal section is connected to the distal section.

This and other embodiments can include one or more of the following features. The nosecone can further include a hollow interior portion configured to receive excised tissue. The nosecone can be flexible. The atherectomy catheter can further include a guidewire channel disposed along an exterior of the nosecone. The guidewire channel can include a distal portion extending along the distal section of the nosecone and a proximal portion extending along the proximal section of the nosecone. The distal portion and proximal portion can be configured to align when the proximal section and the distal section are connected together. The distal portion and proximal portions can be configured to prevent the proximal section and distal sections from rotating relative to one another when a guidewire is placed therethrough. The connection mechanism can further include a tab configured to be gripped through the distal section of the nosecone to rotate the distal section relative to the proximal section to activate or deactivate the connection mechanism. The connection mechanism can further include a cam and ball bearing configured to lock and unlock the proximal section relative to the distal section. The connection mechanism can include a plurality of snap arms configured to extend into the proximal section and to interlock with apertures on the proximal section. The snap arms can each include a tab configured to fit within the apertures. The tabs can be chamfered along a side edge such that rotation of the distal section towards the chamfered edges causes the distal section to automatically unlock from the proximal section. The nosecone can be configured to pivot away from the elongate catheter body to further expose the cutter. The cutter can be configured to move axially into the nosecone to pack tissue.

In general, in one embodiment, an atherectomy catheter includes a catheter body having a catheter body proximal end, a catheter body distal end, a cutting window, a cutter exposable through the cutting window, a nosecone, and a collar. A nosecone has a nosecone proximal end and a nosecone distal end. The nosecone proximal end is configured to couple and decouple from the nosecone distal end. The collar has a collar inner surface configured to maintain a detachable connection between the nosecone proximal end with the nosecone distal end.

This and other embodiments can include one or more of the following features. The nosecone can further include a hollow interior portion configured to receive excised tissue. The atherectomy catheter can further include a locking mechanism for maintaining connection between the nosecone proximal end with the nosecone distal end. The locking mechanism components can be disposed on the nosecone proximal end, the collar, the nosecone distal end, or a combination thereof. The locking mechanism can utilize corresponding threads for mating the detachable nosecone proximal end to the nosecone distal end. The locking mechanism can utilize at least one tab and corresponding aperture for mating the detachable nosecone distal end to the nosecone proximal end. The locking mechanism may not interfere with cutter's ability to extend past the locking mechanism. The nosecone can be rigid. The nosecone can be flexible. The nosecone can include both flexible and rigid regions. The atherectomy catheter can further include a guidewire channel disposed on the nosecone and the catheter body.

In general, an atherectomy catheter includes a catheter body having a catheter body proximal end, a catheter body distal end, a cutting window, a cutter exposable through the cutting window, a nosecone, a collar, and a locking mechanism for maintaining connection between the proximal and distal ends of the nosecone. A nosecone has a nosecone proximal end and a nosecone distal end. The nosecone proximal end is configured to couple and decouple from the nosecone distal end. The collar is configured to maintain connection between the nosecone proximal end with the nosecone distal end. The locking mechanism components are disposed on the nosecone proximal end, the collar, the nosecone distal end, or a combination thereof.

This and other embodiments can include one or more of the following features. The nosecone can further include a hollow interior portion configured to receive excised tissue. The locking mechanism can utilize corresponding threads for mating the nosecone proximal end with the nosecone distal end. The locking mechanism can utilize at least one tab and corresponding aperture for mating the nosecone proximal end with the detachable nosecone distal end. The locking mechanism cannot interfere with the cutter's ability to extend past the locking mechanism. The nosecone can be rigid. The nosecone can be flexible. The nosecone can include both flexible and rigid regions.

In general, an atherectomy catheter includes a catheter body having a catheter body proximal end, a catheter body distal end, a cutting window, a cutter exposable through the cutting window, a nosecone, a collar, and a locking mechanism for maintaining connection between the detachable nosecone and the catheter body. A nosecone has a nosecone proximal end and a nosecone distal end. The nosecone proximal end is configured to couple and decouple from the nosecone distal end. The collar is configured to maintain connection between the detachable nosecone and the catheter body. The locking mechanism includes corresponding threads on the collar, nosecone proximal end, or nosecone distal end adapted to couple the proximal and distal ends of the nosecone.

In general, in one embodiment, an atherectomy catheter includes a catheter body having a catheter body proximal end, a catheter body distal end, a cutting window, a cutter exposable through the cutting window, a nosecone, a collar, and a locking mechanism for maintaining connection between the proximal and distal ends of the nosecone. A nosecone has a nosecone proximal end and a nosecone distal end. The nosecone proximal end is configured to couple and decouple from the nosecone distal end. The collar is configured to maintain connection between the detachable nosecone and the catheter body. The locking mechanism includes at least one tab disposed on the collar having corresponding aperture adapted to mate the proximal and distal ends of the nosecone.

This and other embodiments can include one or more of the following features. The atherectomy catheter can further include a drive system configured to extend and retract the cutter within the nosecone.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

FIG. 1A shows a distal end of an atherectomy catheter having a tissue connection nosecone with a detachable distal end

FIG. 1B is a perspective view of an exemplary coupling mechanism for coupling detachable proximal and distal sections of a nosecone. FIG. 1C shows a cross-section of the coupling mechanism of FIG. 1B. FIG. 1D is a perspective views of a first coupling element of the coupling mechanism of FIG. 1B. FIGS. 1E and 1F shows a perspective view of a second coupling element of the coupling mechanism of FIG. 1B.

FIGS. 2A and 2B show an alternative exemplary coupling mechanism for a nosecone. FIG. 2A shows a coupling element including two tabs. FIG. 2B shows a coupling element including to corresponding apertures and configured to lock with the coupling element of FIG. 2A.

FIG. 3A shows a top perspective view of a portion of an atherectomy catheter having a nosecone with a detachable distal end that is connected through a single tab coupling mechanism.

FIG. 3B shows a bottom perspective view of the portion of the atherectomy catheter of FIG. 3A.

FIG. 4A shows a side perspective view of a portion of a nosecone with a detachable distal end that is connected through a twist mechanism.

FIG. 4B shows a bottom view of the portion of the nosecone of FIG. 4A.

FIG. 4C-4E show the nosecone of FIG. 4A with the collar removed so as to make the twist/aligning features between the proximal and distal ends visible.

FIG. 5A shows an exemplary nosecone having a detachable distal end activated by a cam and ball mechanism.

FIG. 5B shows a the cam and ball mechanism.

FIG. 5C shows a close-up of the nosecone of FIG. 5A in the locked position with the distal portion of the nosecone removed for clarity.

FIG. 5D shows a cross-section through the locked nosecone shown in FIG. 5C.

FIG. 5E shows a close-up of the nosecone of FIG. 5A in the unlocked position with the distal portion of the nosecone removed for clarity.

FIG. 5F shows a cross-section through the unlocked nosecone shown in FIG. 5E.

FIG. 5G shows the nosecone of FIG. 5A with the distal end detached from the proximal end.

FIG. 5H shows a cross-section through FIG. 5B to more clearly show the cam path.

FIG. 6A shows an exemplary nosecone having a detachable distal end activated by a snap mechanism.

FIG. 6B shows the proximal and distal ends disconnected.

FIG. 6C is a cross-section showing the proximal and distal ends connected.

FIG. 7 shows a separable nosecone with monorail guidewire lumen.

DETAILED DESCRIPTION

Described herein are atherectomy catheters including an elongate body, a cutter, and a nosecone configured to collect debulked tissue. The nosecone includes an atraumatic distal end, a proximal end that couples to the remainder of the catheter body, and an interior region for collecting excised tissue. The proximal portion of the nosecone is detachable from the distal portion for ease of for ease of cleaning and/or for quick replacement of the distal portion of the nosecone during an atherectomy procedure.

The nosecones described herein include features that both allow easy coupling of the proximal and distal ends of the nosecone and prevent unwanted decoupling during use. Moreover, the interior surface of the nosecone with detachable distal/proximal portions can be substantially smooth, allowing a cutter to extend therein (e.g., to pack tissue) without hindrance.

The distal end of an exemplary atherectomy catheter 1200 is shown in FIG. 1A, The atherectomy catheter includes a catheter body 1201, a hollow nosecone 1204, an annular rotatable cutter 1210, and a cutter window 1207 through which the cutter can debulk tissue. The hollow nosecone 1204 can be configured to collect tissue as it is removed in the body. Further, in some embodiments, the cutter 1210 can be moved axially into the nosecone 1204 to pack tissue therein. Moreover, in some embodiments, the nosecone 1204 can hinge relative to the catheter body 1201, such as at a pivot point. As shown in FIG. 1A, in some embodiments, the nosecone can include holes 1244 therein for venting. A distal section or end 1205 of the nosecone 1204 can be configured to detach from the proximal portion 1206 of the nosecone 1200 at attachment/detachment point 1226 to allow for ease of removing collected or packed tissue. The attachment/detachment point 1226 can include, for example, one or more coupling elements. Various embodiments of coupling elements are described herein.

FIGS. 1B-1F show an exemplary coupling mechanism 111 that includes a first coupling element 925 configured to interface with a corresponding coupling element 1024 for locking and unlocking of the proximal and distal portions of a nosecone (such as nosecone 1204).

FIG. 1D shows the coupling element 925, which includes a proximal end 930 and a distal end 928. The coupling element 925 includes a generally cylindrical main body with a lumen between the proximal and distal ends. The slots or cutouts 932 a-b are formed through the wall of the main body. Although shown with two slots having a generally rectangular shape, the coupling element 925 can have any number of slots with any shape. The shape of the main body is designed to be inserted into the corresponding coupling element 1024 for attachment.

FIGS. 1E and 1F illustrate the corresponding coupling element 1024 that is configured to releasably attach to the coupling element 925. The corresponding coupling element 1024 is shape set to the coupling element 924 such that coupling element 925 can be inserted into the corresponding coupling element 1024 to form a snug fit (as shown in FIGS. 1B-1C). The corresponding coupling element 1024 has an inner wall 1038 that contacts the outer wall 934 of the coupling element 925 when fitted. Further, the corresponding coupling element 1024 includes protrusions shown as tabs 1036 a-b that project from its main body towards the center. In some embodiments, the tabs 1036 a-b protrude at an angle towards the center of the main body and are configured to extend into the receiving slots 932 a-b.

Thus, in operation, the corresponding coupling element 1024 is placed over the outer wall 924 of the coupling element 925. The proximal end 1032 of the corresponding coupling element 1024 is advanced over the distal end 928 of the coupling element 925. Then the corresponding coupling element 1024 (or the coupling element 925) is rotated relative to the other element to align the tabs 1036 a-b with the slots 932 a-b. To lock the coupling elements, an edge of the slots 932 a-b is slid into the recess 1031 a-b until a portion of the main body of the coupling element 925 is held between a tab surface and the inner wall of the corresponding coupling element 1024. FIGS. 1B-1C shows the corresponding coupling element 1024 surrounding the coupling element 925 with tabs 1036 a-b engaged with slots 932 a-b. The tabs 1036 a-b are received through the slots 932 a-b into an interior of the coupling element 925. The edge of the slots 932 a-b are slid into the recesses 1031 a-b to hold and lock the lateral orientation of the coupling element 925 within the corresponding coupling element 1024. As shown, rotating the corresponding coupling element counter-clockwise disengages the coupling elements and releases the coupling elements from one another.

FIGS. 2A and 2B show variations of the coupling elements shown in FIGS. 1B-1F. For example, FIG. 2A shows a corresponding coupling element 1124 with two tabs 1136 a-b and a plurality of apertures 1105. In some embodiments, the apertures provide for fluid pressure release. FIG. 2B shows a coupling element 1125 having slots 1132 a-c, e.g., configured to interact with tabs 1136 a-b of FIG. 2A. Although the coupling elements of FIGS. 1B-I F and 2A-2B are shown with two or three tabs/slots, it is to be understood that any number of mating structures can be used to form the detachable tissue collection devices.

FIG. 3A shows another embodiment of a nosecone 204 that can be used with an atherectomy catheter. The nosecone 204 includes a distal end 205 that is detachable from a proximal end 206 at coupling mechanism 211. The nosecone distal end 205 is atraumatic.

The nosecone 204 further includes a cutting aperture 207 that allows cutter (e.g., an annular cutter) of the device to be exposed therethrough for cutting and removing tissue. The nosecone proximal end 206 is configured to couple with the remainder of the catheter body, such as at a connection point 202. For example, the catheter body 201 can be coupled with the nosecone 204 proximal to the cutting aperture 207. In some embodiments, the nosecone 204 can be connected at a hinge point so as to hinge away from the catheter body.

Referring to FIGS. 3A and 3B, the coupling between the nosecone 204 distal end 205 and proximal end 206 may include a collar 211. The collar 211, in turn, may be attached permanently to the nosecone proximal end 106 as shown. The collar 211 can include a collar aperture 212 that is able to couple to a corresponding feature (e.g. a tab 119 or other protrusion) on the proximal end 105 of the nosecone 204. The tab 219 can be configured to include an amount of flexibility such that a user is able to push the end of the collar 211 past the tab 219 to align the tab 219 and the collar aperture 212. The insertion of the distal end 205 into the collar 211 can be aided by the angled or beveled distal edge of the collar 211.

Once aligned with the collar aperture 212, the tab 219 can be engaged or locked within the aperture 212 by an extension 221 on the collar 211. The extension 221 is configured to contact the tab 219, causing the tab 219 to pivot (e.g., at a flexion point) with the proximal end of the tab 219 moving radially towards the central axis of the collar 211 and the distal end of the tab 219 moving radially away from the central axis of the collar 211 to engage/attach within the collar aperture 212 and lock the tab 219 in place. Once the tab 219 is locked in place, the proximal and distal ends 206, 205 of the nosecone will then be connected and/or locked together. To disengage the collar 211 from the distal end 205 of the nosecone 204, the user can push on the tab to free the tab from the collar aperture 212 and slide the collar 211 axially away from the distal end 205 of the nosecone 204.

In an alternative embodiment, the collar 211 may be permanently attached to the distal end 205 of the nosecone 204 rather than the proximal end 206. Here, the proximal end 206 of the nosecone 204 may include corresponding features with the collar 211 including tabs with corresponding apertures that are able to mate, corresponding threads that screw together, etc.

In some other variations, the collar 211 may be completely detachable from both the nosecone proximal end 206 and the nosecone distal end 205. In this design, the collar 211 may have two or more coupling features for mating the nosecone proximal end 206 to the nosecone distal end 205. The coupling features on the collar 211 in this example may also be used to properly align the nosecone proximal end 206 with the nosecone distal end 205. For example, the collar may have tabs that mate with corresponding tab acceptors on both the nosecone distal end 205 and the nosecone proximal end 206 for holding the two components together, but in addition, the collar 211 may also have additions features that aid with ensuring that the nosecone distal end 205 is properly aligned with the nosecone proximal end 206. These additional features may include, but are not limited to, protrusions and corresponding apertures or slots.

Turning to FIGS. 4A-4E, another coupling mechanism 310 between the distal end 305 and proximal end 306 of a nosecone 304 is shown. The coupling mechanism 310 for the nosecone 304 employs a twist type motion to engage and disengage the nosecone distal end 305 with the nosecone proximal end 306. The twist coupling mechanism 310 is best shown in FIGS. 4C-4E (the collar 311 has been removed in these figures for clarity). The twist coupling mechanism 310 includes a hooked, curved, or c-shaped extension 315 on the distal end 305 that interlock or mates with a corresponding hooked, curved, or c-shaped extension 316 on the proximal end 306 when the proximal and distal ends 306, 305 are rotated relative to one another. Each extension 315, 316 includes a wave-like curve or bump 326, 325 that fits with the corresponding bump 326, 325 on the opposite side. To connect the proximal and distal portions 306, 305, the two portions can be rotated relative to one another. To release, they can be rotated in the opposite direction.

Referring back to FIGS. 4A-4B, the collar 311 can be clamped over the twist mechanism 310 to keep the extensions 315, 316 from rotating apart during use. The collar 311 can be permanently attached to either the proximal end (as shown in FIGS. 3A-3B) or the distal end. When attached to the proximal end, the collar 311 can have a beveled or angled distal edge to aid in insertion of the distal end 305 therein.

Another exemplary embodiment of a nosecone 504 is shown in FIGS. 5A-5H. As shown in FIG. 5A, the nosecone 504 includes a proximal end 506 and a detachable distal end 505. The nosecone 504 further includes a coupling mechanism 515 configured to allow for attachment and detachment of the distal end 505 of the nosecone 504. Referring to FIGS. 5B and 5G, the coupling mechanism 515 includes a solid plug 571 that fits within, and seals to, the inner diameter of the proximal end 506 of the nosecone 504. The coupling mechanism 515 further includes an annular collar 573 configured to permanently attach to the proximal end 505 of the nosecone. The coupling mechanism 515 connects together by twisting a rotatable tab 525 (which is fixed to the collar 573) to activate a cam 577. When the distal end 505 is locked to the proximal end 506 (as shown in FIGS. 5C and 5D), a ball bearing 527 sits within an outer window 533. When unlocked, however, the ball bearing 525 is pulled back inside the window 533 into the inner slot 531 (as shown in FIGS. 5E-5F).

In use, the user can grab the tab 525 (e.g., through a flexible portion of the distal end 505), insert the plug 571 into the distal end 505, and rotate the tab 525. As shown in FIG. 5G, doing so will cause the peak in the cam 577 to push the ball 527 from the window 531 towards the window 533. Once engaged in the window 533, the ball 527 will prevent future movement of the proximal and distal ends 506, 507 relative to one another. To unlock, the user can rotate the tab 525 in the opposite direction. This will cause the ball 527 to move all the way back into the inner window 531, allowing the distal end 505 to be pulled distally away from the proximal end 506.

The coupling mechanisms 515 is positioned close to the distal tip of the nosecone 504 (e.g., 1-2 inches, such as approximately 1.5 inches away from the distal edge of the cutting window 507). This can advantageously provide for ample room for tissue packing inside the proximal portion 506 and prevent interference of the coupling mechanism 515 with the cutter as it packs tissue.

Another exemplary embodiment of a nosecone 604 is shown in FIGS. 6A-6C. The nosecone 604 includes a proximal end 606 and a detachable distal end 605. The nosecone 604 further includes a coupling mechanism 622 configured to allow for attachment and detachment of the distal end 605 from the proximal end 606. The coupling mechanism 622 includes a solid plug 671 that fits within, and seals to, the inner diameter of the proximal end 606 of the nosecone. The coupling mechanism 622 further includes two snap arms 623 a,b that extend proximally away from the plug 671. The snap arms 623 a,b can further include radially extending tabs 625 a,b that are configured to snap into corresponding snap window 624 a,b on the proximal end 606. In some embodiments, the user can release the distal end 605 by pushing on the tabs 625 a,b. Further, in some embodiments, the tabs 625 a,b can be chamfered at one edge such that either clockwise or counterclockwise rotation can automatically push the tabs 625 a,b to release the coupling mechanism 622.

Again, the coupling mechanism 622 is positioned close to the distal tip of the nosecone 604 (e.g., there can be about 1-2 inches, such as 1.5 inches, from a distal edge of the cutter window 607 to a proximal end of the snap arms). This can advantageously provide for ample room for tissue packing inside the proximal portion 606 and prevent interference of the coupling mechanism 622 with the cutter as it packs tissue.

Referring to FIG. 7, in any of the embodiments described herein, a guidewire lumen 755 can extend down the side of the nosecone. The guidewire lumen 755 can include two interconnectable sections (one section attached to the proximal end 706 and another section attached to the distal end 705). Insertion of the guidewire through the lumen 755 can help keep the proximal and distal ends 706, 705 of the nosecone together. That is, the insertion of the guidewire through the lumen 755 can help prevent rotation of the proximal and distal ends 706, 705 relative to one another when a rotatable or twisting locking mechanism 710 is used to unlock (e.g., any of the embodiments described herein that include twisting or rotation to unlock).

In some embodiments, features on both the nosecone distal end and the nosecone proximal end may aid a user in properly aligning the nosecone proximal end with the nosecone distal end. For example, in some instances, the nosecone proximal end and the nosecone distal end may be angled or biased such that they fit together. To further ensure proper alignment or attachment of these two components, the nosecone proximal end and the catheter distal end may further include features on the angled or biased end surfaces that are configured to mate. In other examples, there may be visual indicators on the nosecone proximal end and the catheter body distal end that aid a user in aligning the two portions.

In some embodiments, the attachment features can include an auditory or physical signal that indicates that the proximal and distal ends of the nosecone are connected (e.g., the detent feature can make a clicking noise to signal locking).

In some embodiments, the attachment mechanisms and distal ends of the nosecones described herein can be reusable. In other embodiments, the distal end of the nosecone is meant as a single use, and the attachment mechanisms cannot be detached and then reattached. For example, the tab features can be configured to break or become unusable after disengaged.

The attachment mechanisms shown with respect to FIGS. 3A-6C have a substantially smooth inner circumference (i.e., on the inside of the nosecone) and are free of tabs or mechanisms that extend radially inwards into the nosecone. This can advantageously prevent the attachment mechanisms from interfering with the movement of the cutter as it is moved into the nosecone (i.e., for packing) and/or prevent pieces of excised plaque or tissue from becoming entangled on radially inwardly protruding extensions of the attachment mechanisms.

In some embodiments, the nosecone attachment mechanisms described herein are a set distance from the cutting window to further eliminate interference with the cutter. Thus, the distance between the attachment mechanism and the cutting window can be, for example, 0.5″-1.0″, such as 0.6″-0.8″, such as approximately 0.68″ or 0.70″. In some embodiments, the distal edge of the cutter, when fully extended, can be positioned just proximal of the attachment mechanisms.

It should be understood that any suitable mechanism or means (e.g. friction fit, mated fit, threaded fit, hooks, securing members, etc.) may be used in addition to, or in place of, the attachment mechanisms described herein to detach a portion or the entirety of a tissue collection device to another device.

Additionally, any suitable materials such as nitinol, stainless steel (e.g. grade 304), or titanium or alloys may be used to form the attachment mechanisms. Coatings including gold or platinum may be used to promote radiopacity.

Any of the features of the described tissue collection devices can be used in combination without departing from the disclosure.

Having a nosecone with detachable sections therein can advantageously be used for flushing or otherwise clearing excised tissue out of the nosecone. That is, after tissue has been excised and collected in the nosecone (such as by packing it into the nosecone through axial movement of the cutter), the distal end or section of the nosecone can be removed, thereby permitting the proximal end to be flushed (e.g., from the cutting window through the open distal end) and/or allowing either the proximal or the distal end to be easily cleared with a tissue removal tool.

Although the above coupling mechanisms have been described as being used to attach and detach to portions of a nosecone, they can also be used to couple other portions of a catheter. For example, in some embodiments, the entire tissue-collection portion of the nosecone can be removable from the rest of the catheter using one of the coupling mechanisms described herein.

Any of the described tissue collection devices can be used with atherectomy or other occlusion crossing devices. In such cases, the atherectomy devices typically include an elongate body and a rotatable tip (with a cutter) at the first distal end of the elongate body and configured to rotate relative to the elongate body. Such devices are described in U.S. Patent Application No. 61/646,843, titled “ATHERECTOMY CATHETERS WITH IMAGING,” filed on May 14, 2012, U.S. patent application Ser. No. 13/433,049, titled “OCCLUSION-CROSSING DEVICES, IMAGING, AND ATHERECTOMY DEVICES,” filed Mar. 28, 2012, U.S. patent application Ser. No. 13/175,232, titled “ATHERECTOMY CATHETERS WITH LONGITUDINALLY DISPLACEABLE DRIVE SHAFTS,” filed on Jul. 1, 2011, U.S. patent application Ser. No. 12/829,277, titled “ATHERECTOMY CATHETER WITH LATERALLY-DISPLACEABLE TIP,” filed on Jul. 1, 2010, and U.S. patent application Ser. No. 12/829,267, titled “CATHETER-BASED OFF-AXIS OPTICAL COHERENCE TOMOGRAPHY IMAGING SYSTEM,” filed on Jul. 1, 2010, International Patent Application No. PCT/US2015/014613, titled “ATHERECTOMY CATHETERS AND OCCLUSION CROSSING DEVICES,” filed on Feb. 5, 2015, U.S. patent application Ser. No. 15/072,272, titled “ATHERECTOMY CATHETERS DEVICES HAVING MULTI-CHANNEL BUSHINGS,” filed on Mar. 16, 2016, and U.S. patent application Ser. No. 15/076,568, titled “ATHERECTOMY CATHETERS AND OCCLUSION CROSSING DEVICES,” filed on Mar. 21, 2016, all of which are herein incorporated by reference in their entirety.

When a feature or element is herein referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another feature or element, there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown can apply to other embodiments. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

Terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items and may be abbreviated as “/”.

Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the exemplary term “under” can encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly”, “downwardly”, “vertical”, “horizontal” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

Although the terms “first” and “second” may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed below could be termed a second feature/element, and similarly, a second feature/element discussed below could be termed a first feature/element without departing from the teachings of the present invention.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” and “comprising” means various components can be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps.

As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions. For example, a numeric value may have a value that is +/−0.1% of the stated value (or range of values), +/−1% of the stated value (or range of values), +/−2% of the stated value (or range of values), +/−5% of the stated value (or range of values), +/−10% of the stated value (or range of values), etc. Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

Although various illustrative embodiments are described above, any of a number of changes may be made to various embodiments without departing from the scope of the invention as described by the claims. For example, the order in which various described method steps are performed may often be changed in alternative embodiments, and in other alternative embodiments one or more method steps may be skipped altogether. Optional features of various device and system embodiments may be included in some embodiments and not in others. Therefore, the foregoing description is provided primarily for exemplary purposes and should not be interpreted to limit the scope of the invention as it is set forth in the claims.

The examples and illustrations included herein show, by way of illustration and not of limitation, specific embodiments in which the subject matter may be practiced. As mentioned, other embodiments may be utilized and derived there from, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. Such embodiments of the inventive subject matter may be referred to herein individually or collectively by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept, if more than one is, in fact, disclosed. Thus, although specific embodiments have been illustrated and described herein, any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description. 

What is claimed is:
 1. An atherectomy catheter comprising: an elongate catheter body; a cutter at a distal end of the catheter body configured to excise tissue from the body; and a nosecone attached to a distal end of the catheter body and configured to hold tissue excised from the cutter, wherein the nosecone includes a distal section, a proximal section, and a connection mechanism therebetween that is configured to allow the distal section to attach and detach from the proximal section during use, further wherein the distal section includes a plug configured to sit within an inner diameter of the proximal section when the proximal section is connected to the distal section; and wherein the plug is configured to be removed from the proximal section when the distal section is detached from the proximal section.
 2. The atherectomy catheter of claim 1, wherein the nosecone further comprises a hollow interior portion configured to receive excised tissue.
 3. The atherectomy catheter of claim 1, wherein the nosecone is flexible.
 4. The atherectomy catheter of claim 1, further comprising a guidewire channel disposed along an exterior of the nosecone.
 5. The atherectomy catheter of claim 4, wherein the guidewire channel comprises a distal portion extending along the distal section of the nosecone and a proximal portion extending along the proximal section of the nosecone, the distal portion and proximal portion configured to align when the proximal section and the distal section are connected together.
 6. The atherectomy catheter of claim 5, further wherein the distal portion and proximal portions are configured to prevent the proximal section and distal sections from rotating relative to one another when a guidewire is placed therethrough.
 7. The atherectomy catheter of claim 1, wherein the connection mechanism further includes a tab configured to be gripped through the distal section of the nosecone to rotate the distal section relative to the proximal section to activate or deactivate the connection mechanism.
 8. The atherectomy catheter of claim 1, wherein the connection mechanism further includes a cam and ball bearing configured to lock and unlock the proximal section relative to the distal section.
 9. The atherectomy device of claim 1, wherein the connection mechanism includes a plurality of snap arms configured to extend into the proximal section and to interlock with apertures on the proximal section.
 10. The atherectomy device of claim 9, wherein the snap arms each include a tab configured to fit within the apertures.
 11. The atherectomy device of claim 10, wherein the tabs are chamfered along a side edge such that rotation of the distal section towards the chamfered edges causes the distal section to automatically unlock from the proximal section.
 12. The atherectomy device of claim 1, wherein the nosecone is configured to pivot away from the elongate catheter body to further expose the cutter.
 13. The atherectomy device of claim 1, wherein the cutter is configured to move axially into the nosecone to pack tissue.
 14. The atherectomy device of claim 1, wherein the plug comprises a solid plug.
 15. The atherectomy device of claim 1, further wherein the nosecone is configured such that the proximal section comprises an open distal end when the distal section is detached from the proximal section. 